It started as a simple afternoon at the movie, just ten days ago. A devoted father bringing his phone so he could check up on his toddler, a retired cop bringing his gun. But before the movie even begins, an argument between the men, both whom served in the Navy escalates to a shocking climax and transforms a wife into pa widow. You're about to meet a woman who was shot by the same bullet that killed her husband. Tonight in an exclusive interview, she tells me how a senseless dispute changed her life in an instant. 30 seconds, my world changed. The pain is still raw for a woman who went to the movies ten days ago with her husband and left the theatre a widow. Did the bullet go right through it. Which finger is it? My ring finger? Th That's part of the what-if, what if it had hit my ring and deflected or hit my hand where it was more solid. The gunshot wound will heal. It's a finger. The real pain is in my heart. Nicole was at her husband's side when he was shot at point blank range by a former Tampa police officer. Thank you, you may step back. Witnesses say he was angry over her husband's refusal to put away his cell phone. The two were married seven years ago. He never met a stranger. Talks to everybody, makes friends with anybody he comes across. It just seemed to work for us. You still talk about him in the presence tense. I don't think it's hit me yet. I don't think I've been able to process it all. It's been a whirlwind. Even though he's gone, he'll still be with me. He's gone but not forgotten. Good girl. Certainly not by his little girl. 22-month-old Alexis. When you see Chad with your daughter, it was just magic. She was his life. He was all about that baby girl. What does she understand? I mean, daddy is not there at night. She talks about daddy all the time. At bedtime, you know, that was his routine. To tuck her into bed. So that's going to be hard because I can never replace that. I can put her to bed but I can never share that bond he had for her. It was a rare day when the couple had time alone, but last Monday they both had the day off. Alexis was teething. If she developed a fever, they would pick her up at day care, but meanwhile, they decided to go see "Lone survivor" at an June scale theatre nearby. Outside, this sign. Inside, plush leather seats and plenty of leg room. So you get your tickets, get your popcorn? Yep, popcorn and soda and twizzlers and sit down and relax a little bit during the previews. Nicole shows me where they were sitting. Not in the very back row, but towards the back. So more in this back section. Slightly offcenter. The large theatre only had a couple dozen thepatrons. They set in for the previews of the 1:20 show. We're very respectful and put our cell phones aroy during the movie. During the previews he had checked his phone one last time to make sure there were no missed messages regarding our daughter. And at that time he just took it out and glanced at it, no noise, no talking. Nothing. There was a brief conversation, less than a minute. A couple exchanged words. The man left the theatre for a couple of minutes and returned a little bit later. We had known that he was going to get management. When he returned, he was by himself. And that was it. 30 seconds later, my world changed. A blink of an eye. So there wasn't any time to think something is about to happen, let's move our seats, this is not cool. It was an exchange of words and I casualty just went Chad, don't even worry about it. Just a natural gesture, and that's when my life changed. So unexpected. Never thought there was any type of aggression or fight or anything. Just two guys just kind of mind your own business. That was it. The shooter, 71-year-old retired police officer Curtis reeves, who claims he acted in self-defense. Reeves has a distinguished record with the Tampa police department, credited with starting their S.W.A.T. Team. His lawyer claims reeves felt threatened by Chad oulson, who at 6'4" was nearly 30 years younger, an imposing figure. He was hit in the face with an unknown object. At that point in time, he has every right to defend himself. Another patron says it was popcorn. Did your husband throw popcorn at the man sitting behind him? Not that I'm aware of. Some people have said look, he was an old guy, 71 years old. Your husband was young and vital and that he felt threatened. Your husband was a big guy. That when your husband stood up, that was the moment where he felt threatened. Your husband did stand? He did stand. Yes. But he was not a small guy himself. And just by standing is not a threat. We all stand up. He was steps above us, the other guy, he was towering over us. How is that a threat? Can nobody in the world stand up in a movie theatre without having to fear that they are in jeopardy of losing their life? That makes no sense. That makes no sense at all. Her lawyers say that Florida's controversial stand your ground law does not apply in this case. Stand your ground requires that the person it's being used against has to be an attacker and I don't think I've heard anything to suggest that any of the conduct is even remotely close to what I would say warrants being an attack to even rise to the level where he can contemplate using deadly force. You're only supposed to use deadly force if you believe you're in danger or somebody else is in danger. In fear of your life. Or great bodily harm. Further more, they argue the fact that another woman has come forward and said that Curtis reeves also confronted her over her cell phone suggests reeves was looking for trouble. He's like, can you do me a favor? Can you please just stop texting? From what I hear about it, I see him being the cop of cops. I mean, he founded S.W.A.T. In Tampa and he was known as being a great cop. But I think that maybe the power got to his head and he doesn't have that power anymore because he's no longer a law enforcement officer. He's relegated himself in his own mind to a mall cop. And he's trying to take justice into his own hands. And he doesn't have this ability. Someone said earlier, like who in an empty movie theatre chooses the seat behind the 6'4" guy anyway? The mall cop. Somebody who's looking for trouble. He must have replayed so many to times in your head all of the would have, could have, should have. They never end. And it's so hard. What if this, what if that. But it doesn't do any good because it's not going to change anything and it's not going to bring him back. For someone who didn't know him, do you think he would seem threatening or imposing? Absolutely not. Absolutely not. He was just so friendly and outgoing. And, you know, he would talk to anybody. Just let stuff roll off his shoulders. Nothing ever really seemed to bother him. So he wasn't the kind of guy itching for a fight? Oh, no. Not that type of personality at all. Why did you decide to do an interview? To tell husband story, because he deserves it. There's a lot of, you know, incorrect facts out there and it's important to know that he did not instigate this. He was not an aggressor. He did not make threats. He did not do anything wrong. He did not do anything wrong, and I was right there by his side and I want to be able to share that. This man acted ed out of control, and for no reason. I know you want to see justice done. What does justice look like to you? For him to stay behind bars for the rest of his life. He can't undo the pain and the hurt that he's caused me and my daughter and his family. His mom and his brother and his sister. We've been sentenced, too. To a lifetime of pain and hurt. And there's no excuse for what he did. So I don't want him to see daylight ever again.

This transcript has been automatically generated and may not be 100% accurate.